Avalanche Forecast

Archived

Dec 13th, 2024–Dec 14th, 2024

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Jasper, Brazeau, Churchill, Cirrus-Wilson, Fryatt, Icefields, Maligne, Marmot, Miette Lake, Pyramid.

New windslabs will form as new snow falls.

Multiple crusts from earlier in the season are still present near the bottom of the snowpack and have the potential to be produce avalanches. Consider digging down and having a look in the area you are skiing or riding in.

Confidence

Moderate

Avalanche Summary

One natural size 2 avalanche, failing on the early season crust, and two natural size 2 windslabs were observed on alpine southwest and south aspects on Monday, December 9th near the Icefields.

Snowpack Summary

Incoming snow will fall during windy conditions, potentially forming a thin but reactive windslab. This may form overtop a surface hoar layer that has been found in sheltered Alpine areas down 40-60 cm's. At the bottom of the snowpack there are a variety of early season crusts with large faceted crystals above and below. Both of these layers have been producing sudden planar, compression test results in test profiles.

Weather Summary

Saturday:

Snow forecasts vary, could see accumulation up to 11 cm through the day. Alpine temperature high of -5 °C. Ridge wind from the southwest 20 km/h gusting to 60 km/h. Freezing level at valley bottom.

Sunday:

Cloudy with scattered flurries accumulating up to 4cm of snow. Alpine temperature: low of-12 °C and a high of -8 °C. 15km/h ridge wind gusting to 45 km/h. Freezing level at valley bottom.

Terrain and Travel Advice

Be mindful that deep instabilities are still present in the snowpack.
Be careful as you transition into wind-affected terrain.

Problems

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.